Globally – Activates a protection group on both clusters where the protection group is configured.

On the primary cluster only – Secondary cluster remains inactive.

On the secondary cluster only – Primary cluster remains inactive.

Activating a Hitachi TrueCopy protection group on a cluster has the following effect on the data replication layer:

The data replication configuration of the protection group is validated. During validation, the current local role of a protection group is compared with the aggregate device group state as described in Table 2–3. If validation is successful,
data replication is started.

Data replication is started on the data replication device groups that are configured for the protection group, no matter whether the activation occurs on a primary or secondary cluster. Data is always replicated from the cluster on which the local role of the protection group
is primary to the cluster on which the local role of the protection group is secondary.

Application handling proceeds only after data replication has been started successfully.

Activating a protection group has the following effect on the application layer:

When a protection group is activated on the primary cluster, the application resource groups that are configured for the protection group are also started.

When a protection group is activated on the secondary cluster, the application resource groups are not started.

The Hitachi TrueCopy command that is used to start data replication depends on the following factors:

Aggregate device group state

Local role of the protection group

Current pair state

The following table describes the Hitachi TrueCopy command that is used to start data replication for each of the possible combinations of factors. In the commands, dg is the device group name and fl is the fence level that is configured for the device
group.

Table 2–4 Commands Used to Start Hitachi TrueCopy Data Replication

Aggregate Device Group State

Valid Local Protection Group Role

Hitachi TrueCopy Start Command

SMPL

primary or secondary

paircreate -vl -g dg -f fl

paircreate -vr -g dg -f fl

Both commands require that the horcmd process is running on the remote cluster.

Regular Primary

primary

If the local state code is 22, 23, 25, 26, 29, 42, 43, 45, 46, or 47, no command is run because data is already being replicated.

If the local state code is 24, 44, or 48, then the following command is run: pairresync -g dg [-l].

If the local state code is 11, then the following command is run: paircreate -vl -g dg -f fl.

Both commands require that the horcmd process is running on the remote cluster.

Regular Secondary

secondary

If the local state code is 32, 33, 35, 36, 39, 52, 53, 55, 56, or 57, no command is run because data is already being replicated.

If the local state code is 34, 54, or 58, then the following command is run: pairresync -g dg

If the local state code is 11, the following command is run: paircreate -vr -g dg -f fl

Both commands require that the horcmd process is up on the remote cluster.

Takeover Primary

primary

If the local state code is 34 or 54, the following command is run: pairresync -swaps -g.

If the local state code is 11, then the following command is run: paircreate -vl -g dg -f fl.

The paircreate command requires that the horcmd process is running on the remote cluster.

Takeover Secondary

secondary

If the local state code is 24, 44, 25, or 45, the following command is run: pairresync -swapp -g dg.

If the local state code is 11, the following command is run: paircreate -vr -g dg -f fl.

Both commands require that the horcmd process is running on the remote cluster.

Next, the protection group, tcpg, is activated by using the geopg start command.

phys-paris-1# geopg start -e local tcpg

The Sun Cluster Geographic Edition software runs the paircreate -g devgroup1 -vl -f async command at the data replication level. If the command is successful, the state of devgroup1 is provided in the output of the pairdisplay command: